[1] We report the results of thermal convection experiments in a rapidly rotating hemispherical shell with a heterogeneous heat flux at the outer boundary to model the effect of a thermally heterogeneous core-mantle boundary on the convection in the Earth's outer core. A parameter study is made by varying the heat flux, size, and location of an anomalously heated patch for a range of Rayleigh numbers at similar to10(8) and a fixed Ekman number 4.7 x 10(-6). Experiments show that fully developed, boundary-driven convection occurs when the radial convective heat transfer from the heater exceeds that of the surrounding boundary region. The flow consists of a large-scale cyclonic circulation originating from the heater and includes a radially extending spiralling front with a jet. The front is stationary when the sectorial high heat flux region is imposed at low latitudes but becomes unstable when it is imposed at high latitudes. The ratio of applied heat which is partitioned to radial and lateral heat transfer becomes fixed in this regime. Measurements also indicate that there is a close correlation between the flow direction and the statistics of temperature fluctuations. Applied to the Earth, the experiments suggest that there are two scales of flows in the core: fine-scaled jets and slower, large-scale flows. The large-scale hemispherical structure of the core can be interpreted in terms of the boundary-driven flow driven by the high heat flow region beneath east Asia.
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Ctr High Pressure Sci & Technol Adv Res HPSTAR, Shanghai, Peoples R China
Hiroshima Univ, Dept Earth & Planetary Syst Sci, Higashihiroshima, JapanCtr High Pressure Sci & Technol Adv Res HPSTAR, Shanghai, Peoples R China
Zhang, Youjun
Sekine, Toshimori
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Ctr High Pressure Sci & Technol Adv Res HPSTAR, Shanghai, Peoples R China
Hiroshima Univ, Dept Earth & Planetary Syst Sci, Higashihiroshima, JapanCtr High Pressure Sci & Technol Adv Res HPSTAR, Shanghai, Peoples R China
Sekine, Toshimori
Lin, Jung-Fu
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Ctr High Pressure Sci & Technol Adv Res HPSTAR, Shanghai, Peoples R China
Univ Texas Austin, Dept Geol Sci, Jackson Sch Geosci, Austin, TX USACtr High Pressure Sci & Technol Adv Res HPSTAR, Shanghai, Peoples R China
Lin, Jung-Fu
He, Hongliang
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China Acad Engn Phys, Natl Key Lab Shock Wave & Detonat Phys, Mianyang, Peoples R ChinaCtr High Pressure Sci & Technol Adv Res HPSTAR, Shanghai, Peoples R China
He, Hongliang
Liu, Fusheng
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Southwest Jiaotong Univ, Coll Phys Sci & Technol, Chengdu, Sichuan, Peoples R ChinaCtr High Pressure Sci & Technol Adv Res HPSTAR, Shanghai, Peoples R China
Liu, Fusheng
Zhang, Mingjian
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Southwest Jiaotong Univ, Coll Phys Sci & Technol, Chengdu, Sichuan, Peoples R ChinaCtr High Pressure Sci & Technol Adv Res HPSTAR, Shanghai, Peoples R China
Zhang, Mingjian
Sato, Tomoko
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Hiroshima Univ, Dept Earth & Planetary Syst Sci, Higashihiroshima, JapanCtr High Pressure Sci & Technol Adv Res HPSTAR, Shanghai, Peoples R China
Sato, Tomoko
Zhu, Wenjun
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China Acad Engn Phys, Natl Key Lab Shock Wave & Detonat Phys, Mianyang, Peoples R ChinaCtr High Pressure Sci & Technol Adv Res HPSTAR, Shanghai, Peoples R China
Zhu, Wenjun
Yu, Yin
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China Acad Engn Phys, Natl Key Lab Shock Wave & Detonat Phys, Mianyang, Peoples R ChinaCtr High Pressure Sci & Technol Adv Res HPSTAR, Shanghai, Peoples R China